Center punch with hammer and magnifier



1961 c. J. KOTCHAN 3,011,258

CENTER PUNCH WITH HAMMER AND MAGNIFIER Filed May 23, 1958 INVENTOR. CH ARLE S J. KOTOHAN mama 3,011,258 CENTER PUNCH WITH HAMMER] AND MAGNIFIER Charles I. Kotchan, 3404 Freeman St, San Diego 6, Calif. Filed May 23, 1958, Ser. No. 737,402 2 Claims. (Cl. 30-667) The present invention relates generally to hand tools and more particularly to a center punch with hammer and magnifier.

The primary object of this invention is to provide a center punch having an attached slidable hammer and a magnifier, with a unique adjustable mounting, to give a magnified view of the working area for greater accuracy.

Another object of this invention is to provide a center punch in which the hammer is of a special tapered form to cause a minimum of visual obstruction while requiring a small impact area so that the full force of the hammer is imparted to an anvil closely adjacent to the working point thereof without interfering with the operators vision of the work.

A further object of this invention is to provide a center punch in which the hammer is fitted with a magnet which holds the hammer in the raised position, well above the magnifier and ready for quick release, thus making the tool easily operable with one hand.

A specific object of this invention is to provide a center punch having a magnifier which is mounted on a double ball joint whose pivot centers are radially offset from the punch and permit maximum useful adjustment of the magnifier for distance and viewing angle without interfering with the use of the punch, a further specific object is to provide means in such a tool for the vertical, two position adjustment of the magnifier assembly as a whole, making it possible to employ two ranges of magnification with the same equipment.

Still another object of this invention is to provide a center punch in which the punch is easily interchangeable and may be replaced by a prick punch or a scriber point, or a combined reversible tool, which can also be used with the magnifier for accurate work.

Another object of this invention is to provide a center punch which is adapted for fabrication from many different materials, so that the choice of material can be according to the dictates of availability and price considerations, the exact sizes and proportions being matters easily determined to suit particular conditions and needs.

Another object of this invention is to provide a center punch which is practicable and inexpensive to manufacture.

Finally, it is an object to provide a center punch which is simple and convenient to use and which will give gen erally efiicient and durable service.

With these and other objects definitely in View, this invention consists in the novel construction, combination and arrangement of elements and portions, as will be hereinafter fully described in the specification, particularly pointed out in the claims, and illustratedin the drawing which forms a material part of this disclosure, and in which:

FIGURE 1 is a perspective view of the complete center punch with hammer and magnifier;

FIGURE 2 is a sectional view taken on the line 22 of FIGURE 1;

FIGURE 3 is a sectional view taken on the line 3-3 of FIGURE 2;

FIGURE 4 is a fragmentary sectional view similar to a portion of FIGURE 2, showing a scriber point fitted and the magnifier support reversed to secure a second range of adjustment; and

FIGURE 5 is a fragmentary sectional view similar to 3,911,258 Patented Dec. 5, 1951 FIGURE 4, showing a combination, reversible punch and scriber point used with a slightly modified form of the device.

Similar characters of reference indicate similar or identical elements and portions throughout the specification and throughout the views of the drawing.

Referring now to FIGURES l to 3 of the drawing, the pointed tool tip, first, illustrated as a center punch, comprises a shank 10, preferably of round bar stock, on which is mounted a slidable hammer 12, said hammer having a large cylindrical head portion 14 with a knurled gripping surface 15. Recessed into the head portion 14 is a ring shaped magnet 16 which is held in place by acover plate 17, the remainder of the hammer below said head portion being shaped to form an inwardly tapered lower portion 18. Fixed to the upper end of the shank It} is a cap 20 which is slightly larger than the diameter of said shank and serves to prevent removal of the hammer 12, the specific form of the cap not being critical. The cap 20 is of steel or other magnetic material, while the shank 10 and the body of the hammer 12 and cover plate 17 are non-magnetic. The lower end of the shank It) has an internally screw threaded bore 22 to receive the screw threaded end 24 of a punch tip 26, said punch tip having an enlarged knurled boss 28 at the base of the screw threaded portion to facilitate its insertion and removal. The punch tip 26 has a tapered stem 30 and a conventionally shaped point 32 which is suitably hardened.

Secured between the boss 28 and the shank 19 is a radially extending support tongue 34, drilled at one end to fit over the screw threaded end 24, and this end of the tongue constitutes an anvil against which the hammer strikes. The magnifying lens assembly will now be described. The tongue 34 has, at its outer end, a threaded bore in which a fixed ball post 36 is securable in two positions. The ball post 36 is part of a double ball joint, the other portions of which include a ball lug 38 secured to the edge of a lens mounting ring 40, said'ball lug and ball post being clamped between opposite ends of a pair of socket-defining link plates 42 held together by a transverse clamp screw 44 between the ball elements. The link plates 42 have small confronting, open sockets 46 at each end to receive the ball elements of the ball post 36 and ball lug 38 and to constitute an easily adjustable, swivelling joint assembly. The lens ring 40 holds a suitable magnifying lens 48 which is secured by a retaining ring 50, such mountings being conventional.

In use, the point 32 is placed on the position to be marked, with the shank 10 held upright. The hammer 12 is then raised on the shank 10, as indicated in dash line in FIGURE 2, so that the magnet 16 is attracted to the cap 20 and holds the hammer in the raised position. When ready, the hammer 12 can be pushed away from the cap 29 with one finger and allowed to fall, the impact of the falling hammer driving the point into the surface being marked. The configuration of the hammer 12 with its tapered lower portion 18 results in the full force of the blow being directed to a correspondingly small anvil perfectly centered on the axis of the center punch so that the blow is very effective, and this same configuration and arrangement permits maximum visibility of the Work. By adjusting the lens 48 to the most convenient position on its ball joint support, a desirable magnification of the specific work area may be achieved, thus permitting the operator to assume a normal working position without excessive stooping or eye strain, and also permitting extremely accurate work with a minimum ofefr'ort.

In FIGURE 4, the support tongue is shown inverted so that the ball post is above the tongue. This position raises the complete lens assembly and permits full angular adjustment of the lens 48 at a greater distance from the work area for higher magnification. Thus by merely reversing the support tongue 34, two ranges of magnifica tion are possible, each with full positional adjustment of the lens and viewing angle. Furthermore, as illustrated in FIGURE 4, the punch tip may be replaced by a scriber tip 52 having a knurled boss 54 and a screw threaded end 56 which fits into the bore 22 in the shank 10. The main difference between the scriber tip 52 and the punch tip 26 is in the more slender stem 58 and the point 66 which is elongated and sharpened correctly for scribing purposes.

A slight modification of the tool is illustrated in FIG- URE S, in which a combination tip 62 is used, said combination tip being double ended and having a punch tip 64 and a scriber tip 66 separated by a central boss 68.

On both sides of the boss 68 are screw threaded portions 70 to fit into the screw threaded bore 72 of the modified shank '76, which has a deep internal socket 74 to receive the end of the combination tip which is not currently in use. Thus the tip 62 can be quickly reversed for scribing or center punching. Obviously a prick punch can be substituted for the center punch or scriber.

It will be evident that the combination of the doubleball jointed lens with the hammer actuated punch provides a useful tool for accurate marking work. The reversibility of the lens support further extends the useful range of magnification and viewing positions, so that the work can always be viewed from a comfortable working position.

It is noteworthy that the present tool, with the hammer preferably removed and with a scriber tool tip inserted as in FIGURE 4, is ideal for use in precision layout and the same tool then can be adapted, by addition of the hammer and replacement of the scriber tool tip by a center punch tip 26 for the obvious alternative use.

The foregoing specification and the drawing are proposed as illustrative rather than limiting, and I wish to be limited, as to the scope of my invention, only by the following claims.

I claim:

1. The combination comprising: a shank of a nonmagnetic material having an axial hole in one end thereof; a hammer slidably mounted on said shank, said hammer having a head portion with a magnet afiixed thereto, said hammer also having an inwardly tapered lower portion extending toward the hole-end of said shank, said in- 4 wardly tapered lower portion constituting a striking portion; a pointed tool tip having a boss removably positioned in said axial hole of said shank, said tool tip boss acting as an anvil; a cap of magnetic material positioned at the other end of said shank, whereby the magnetic attraction between said magnet and said cap holds said hammer in an elevated position until finger pressure overcomes said magnetic attraction, whereupon the weight of said hammer causes said hammer to fall and strike said anvil.

2. A tool comprising: a shank of a non-magnetic material having an axial threaded hole at one end thereof; a. substantially conical hammer having an axial bore slidably mounted onsaid shank, said hammer having a large head portion with an annular magnet fastened therein to encircle said shank, said hammer having a tapered portion converging toward said threaded-hole end of said shank, the end of said tapered portion constituting a striking portion considerably smaller than said head portion; a pointed tool tip removably threaded into said threaded hole, said tool tip having a boss that fits against the end of said shank, said tool tip boss acting as an anvil; a cap of magnetic material positioned at the other end of said shank, whereby the magnetic attraction between said annular magnet and said cap holds said hammer in an elevated position untilfinger pressure overcomes said magnetic attraction, whereupon the weight of said hammer causes said hammer to fall and strike said anvil, said tapered portion of said hammer causing a minimum of visual obstruction while directing the entire force of the hammer blow to said anvil.

References Cited in the file of this patent UNITED STATES PATENTS 1,170,422 Denman Feb. 1, 1916 1,175,274 Klorer Mar. 14, 1915 1,449,136 Yates Mar. 20, 1923 1,455,441 Hodny May 15, 1923 1,685,707 Keedy Sept. 25, 1928 2,455,972 Bowditch Dec. 14, 1948 2,623,774 Hubbard Dec. 30, 1952 2,663,936 Lepkowski Dec. 29, 1953 2,732,761 Bender et al. Jan. 31, 1956 2,813,511 Kersten Nov. 19, 1957 2,909,351 Pratt a Oct. 20, 1959 

